Naomi Watts to Star in 'Game of Thrones' Prequel for HBO

The pilot, created by Jane Goldman and George R.R. Martin, is set thousands of years before the events of the flagship.

HBO has found the cornerstone of its Game of Thrones prequel.

Two-time Oscar nominee Naomi Watts has been tapped to star in the as-yet untitled project from creator Jane Goldman and George R.R. Martin.

The drama, picked up to pilot in June, is set thousands of years before the events of the HBO flagship. The story chronicles the world's descent from the golden Age of Heroes into its darkest hour. A logline from the network teased the plot without divulging any specifics: "Only one thing is for sure: From the horrifying secrets of Westeros' history to the true origin of the White Walkers, the mysteries of the East to the Starks of legend — it's not the story we think we know."

Watts will play a charismatic socialite hiding a dark secret. The character's name is not being revealed.

The pilot is based on a story from Goldman and Martin, with the teleplay credited to Goldman. Goldman will also serve as showrunner. In addition to Goldman and Martin, executive producers on the series include current Game of Thrones producer Vince Gerardis, as well as Damages and Bloodline co-creator Daniel Zelman and Jim Danger Gray. Chris Symes will serve as a co-EP.

Goldman and Martin's Game of Thrones prequel is the first of several potential series set in the world of Westeros to move forward at HBO beyond the script phase. In May 2017, a multitude of writers were revealed by the pay cabler to be working on what Martin himself has described as "successor shows." Those writers include Goldman, Max Borenstein (Kong: Skull Island), Brian Helgeland (Legend), Carly Wray (Westworld) and Game of Thrones veteran Bryan Cogman. Game of Thrones creators and showrunners David Benioff and Dan Weiss are not involved in the successor show effort, focusing instead on the forthcoming final season of Game of Thrones after more than a decade spent wandering the world of the Seven Kingdoms.

Speaking previously with The Hollywood Reporter, HBO programming president Casey Bloys said that any Game of Thrones successors, if greenlighted, would not air "until at least a year after the final season." The exec also added that he did not expect every one of the scripts to move forward beyond the page.

For her part, Watts has earned two lead actress Oscar nominations (for 21 Grams and The Impossible) and also counts starring roles in such films as Mulholland Drive, King Kong and Birdman. On the TV side, her credits include Showtime's Twin Peaks revival and Netflix's Gypsy, the latter of which she also executive produced. The actress most recently starred in Ophelia and will next appear in Once Upon a Time in Staten Island, The Wolf Hour, Boss Level and Luce. Watts is repped by CAA, Linsten Management, Untitled Entertainment and Hansen Jacobson.